the offshore region beyond the continental slope thermos teric effect dominates 

 the annual cycle of total steric height, whereas near the coast over the con- 

 tinental shelf halosteric effect controls the height. In between, over the 

 slope, both temperature and salinity effects contribute almost equally to the 

 annual cycle of height. Offshore, the annual change of steric height relative 

 to 1000 db resembles that relative to 100 db , but as the coast is approached, 

 the change due to the deeper water becomes more important. The heat budget 

 within the upper 100 db of water determines most of the annual range of steric 

 height offshore, but near the coast both dilution due to precipitation and 

 runoff in winter and concentration due to upwelling of cool, saline water in 

 summer govern the annual cycle of height. The annual variation of coastal, 

 baroclinic currents appears to account for the observed annual range of 

 adjusted mean sea- level along the coast. Local currents seem to be the main 

 factor affecting coastal sea-level and not the general, large-scale oceanic 

 circulation offshore. Considerable interannual variability of steric height 

 is present everywhere along the Line, but it is difficult to determine any 

 well-defined periodicity in the time-series data. "Spectral" maxima at 

 approximately 6,4, 3 and 2 years in addition to the strong annual period are 

 present at various locations along the Line but only the six-year cycle at 

 Station P can be considered reliable. Due to the limited amount of data along 

 the Line, it is difficult to assign significance to these results. In the 

 open ocean the interannual variability appears to be related to the time- 

 integrated divergence of the Ekman transport. (Authors). 



340 THOM, B. G., and CHAPPELL, J. 1975. "Holocene Sea-Levels Relative to 

 Australia," Search . Vol 6, No. 3, pp 90-93. 



In this report the authors present new results and evaluate recently 

 published data to demonstrate that Holocene sea- level change relative to 

 Australia differed substantially from the North Atlantic pattern. The dif- 

 ferences are discussed in the light of new interpretations of global isostasy. 

 (Introduction) . 



341 THOM, B. G., and CHAPPELL, J. 1978. "Holocene Sea-Level Change: An 

 Interpretation," Philosophical Transactions, Royal Society of London. A. 

 Mathematical and Physical Sciences . Vol 291, pp 187-194. 



Interpretation of factors responsible for land- sea- level change in areas 

 such as the Great Barrier Reef involve an appreciation of not only the field 

 evidence purporting to show change, but also the theoretical models which 

 attempt to explain depth variations in shorelines of a given age. Relative 

 movements in sea- level in Holocene time may result from a number of factors 

 operating either external to the study area (e.g. glacio-eustatic , and broad- 

 scale hydro- isostatic deformation of the globe resulting from the last 

 deglaciation and sea-level rise) , or those whose effects are essentially local 

 (e.g. changes in circulation and tidal levels within partially enclosed water 

 bodies induced by sedimentation or biogenic reef growth, meterological changes 

 affecting the magnitude and frequency of storminess, regional flexures and/or 

 faulting, and hydro-isostatic deformation of shelves and adjacent coasts 



157 



